Where did they get that silly idea that ten warriors (or was it a dozen?) would grow from where a dragon's tooth was sown in the ground? Did it have to do with the "strength of ten because the dragon killer's heart was pure?" If you planted a claw, would you get some mages? How about a knuckle? How much for just a wyvern's tooth?
Frankly, there ought to be a metaphysical exchange program with rules and regulations, and maybe overseers. Wouldn't do to get 10 and a half warriors, now, would it? What if the dragon's tooth had a cavity? What do mama dragons tell baby dragons about the tooth fairy? How many sets of teeth does your average dragon have; can we get armies? What are the properties of these warriors? Do they smell like sulphur? Are they cross-pollinated with Mary Contrary's maidens-all-in-a-row?